Two ministers have warned Irish Water its staff should not be entitled to bonuses.

Joan Burton, Minister for Social Protection, joined junior minister Brian Hayes who suggested employees of the state monopoly should not be in line for salary top-ups.

Irish Water managing director John Tierney has revealed that the 500-plus staff were entitled to bonuses of up to 6% of their salaries.

But Ms Burton said the Government would not consider reviving a culture last seen in the Celtic Tiger years.

"We are in a slow recovery. We are getting people back to work but I do not see any room in this country for going back to a bonus culture," she told RTE.

Mr Hayes, junior minister at the Department of Finance, said the idea of bonuses for Irish Water staff was not justified and that the Government was firm in its policy of not allowing bonuses in the semi-state sector.

The total set-up cost of Irish Water is expected to reach 180 million euro.

Mr Tierney also said that Environment Minister Phil Hogan was aware last year of the money which would be spent to establish the company.

Some 50 million euro has been spent on outside help and that figure could grow to nearly 85 million euro.

IT giant IBM will have been paid 44.8 million euro by 2015, Accenture 17.2 million euro, Ernst & Young 4.6 million euro and KPMG 2.2 million euro.

A further 13.3 million euro will have been paid out on smaller contracts between now and then.

Mr Tierney, who earns 200,000 euro a year, defended the huge outlay, insisting that once up and running, the national utility will have saved the state 2 billion euro by 2021.

It also claimed it saved 58 million euro in software licences by using the same IT systems and processes as Bord Gais for billing, asset management and utility financial systems.

Later, Mr Hogan defended the spend on setting up Irish Water.

"You can't set up a new utility on fresh air," he said.

"The people that are being critical of setting up a new utility will have to tell the Irish people what cuts in expenditure or increases in taxation that they are prepared to bring in that we would have got to get good-quality water and a good quantity of quality water."

Mr Hogan also said that details on the contracts Irish Water has signed to date were "not my business".

The Commission for Energy Regulation, which is expected to regulate the rates for consumers, said the charges will be in place from October 1.

A public consultation is planned in April to determine the structure of charges for Irish Water bills such as whether there will be a flat or fixed rate for the service and how variable rates for usage will kick in.

In June a second consultation is planned to determine that actual meter-based rates to be charged for the use of water. A final decision is due in August.

It is understood that Irish Water is working on the basis that consumers will be asked to pay a flat-rate fee for the service as well as metered charges.

The level of free allowances for some consumers is to be set by the Government.

Elsewhere, Public Accounts Committee chairman John McGuinness has said Irish Water should be audited by the Comptroller and Auditor General.

Sinn Fein president Gerry Adams later called on Mr Hogan to resign, claiming he had been involved in a series of debacles.

"He is incompetent," he said.

"He has been involved in too many debacles.

"Minister Hogan should resign immediately and the government should abandon its regressive policy on water provision."